Orlovich, Drinnan & Ladiges, Floral development in the Metrosideros group 
707 
Fig. 14. (left) Floral development of Xanthostemon verlicillatm. a, young half flower bud with 
three petal primordia (P). Sepals have been removed. The floral apex is beginning to invaginate. 
No stamen primordia are visible at this stage (x 160); b, two petal primordia. Stamen primordia 
are just visible as small swellings in front of each petal primordium (arrows) (x 130); c, half 
flower bud. Stamens are initiated in a ring around the rim of the developing hypanthium (x 95); 
d, flower bud with several rows of stamen primordia (x 130); e, half flower bud. Stamen 
primordia in the second or lower rows are not preferentially initiated opposite petals however 
they are arranged in more or less vertical columns (x 125); f, part of a flower bud showing two 
petals and developing stamens. The stamens are initiated in vertical columns and are tightly 
packed (x 100); g, part of a flower bud showing the initiation of new stamen primordia in 
available spaces between older ones (x 110); h, flower bud with sepals (K) and petals (P) 
removed. Stamens in the first row appear to be clustered around the petals due to swelling of 
the petal base (x 95); i, mature flower bud with sepals (K) and petals (P) removed. Stamens are 
beginning to elongate. The region of hypanthium opposite each sepal has small hairs. The 
hypanthium is expanding in the antesepalous regions and there are clusters of colleters (C) in 
this position (x 15). (from DAO 36). 
Fig. 15. Lysicarpus angiistifolius. Mature half flower (x 14). (from PGW 569). 
